Child resistant closures of the two-piece type, such as disclosed in U.S. Pat. No. 3,857,505, are of the "Press and Twist" type where an outer cap with engaging drive lugs is held away from complimentary drive lugs on an inner cap by spring members between the two caps. The spring members carried by the outer cap may engage ramp style lugs and effect rotation of the caps in the cap applying direction to apply the cap to a threaded container neck or finish. When the outer cap is rotated in the opposite direction, the springs ride up the ramps and do not rotate the inner, threaded cap from the container.
When the outer cap is "pushed" or pressed down relative to the inner cap, the spring members will permit the complimentary drive lugs to be interengaged and rotation of the outer cap will be transmitted to the inner cap to permit removal of the inner cap from the container.
While the foregoing patented closure is a successful and widely used commercial closure for products that may be harmful to children, it has recently become a concern that the opening of these containers can be effected without leaving any evidence of the fact of its opening.
The ability to apprise the consumer of the previous tampering of the closure and container, so that he may be aware that possible tampering with the contents had occurred, is a significant and important consideration in the marketing of some over-the-counter products.
A recently issued U.S. Pat. No. 4,371,088 discloses a tamper indicating closure wherein an inner cap 12 is covered by an outer cap or "driver top" 14. The driver top may be depressed to bring lugs 40 into engagement with ribs 28 of the cap 12. When the displacement is made, head 62 of an indicator having a stem 64, is separated from the outer cap. When the indicator element is displaced, webs are fractured, and the element may fall away from the outer cap.